Presta valves
 

New to road bikes. Presta bikes are a pain.

I keep bending the valves on continental tubes. i have a park tools air pump.

Im doing something wrong?

Careful how you are filling it up. As your pumping, you most likely are twisting your hand perpendicular to the wheel, that will cause the bends in the valve. I only have a frame pump for backup now, I got a cheap co2 inflator and it made things not only much quicker, but I dont bend valves as easy anymore lol.

It's easy to bend presta valves with a direct attachment frame pump. Use a floor pump at home or in car and look for a frame pump with a short flexible hose. I use a Topeak Road Morph and Lezene frame pumps and they work very well.

If you are using one of the hand pumps intended to be carried on rides, there is a trick to using them. First, press the pump on square with the valve. Let's say your bike is leaning against a wall. Rotate the wheel 'till the valve is on top. Hold the pump horizontally with the gasket pointing up. Align the gasket with the valve, then push the pump up straight. Before you pump, place your left hand (assuming you rare right handed and pump with your right arm) so your fingers go around the spoke to the left of the pump. then the pump head, Wrap your thumb around the top of the tire. Now, when you pump, the pump head is staying square and your pumping force is going into your hand, the tire and the spoke, not the pump head and therefore the valve. When you finish, simply hold the pump barrel with one hand and knock the pump down sharply with your other hand near the head.

I didn't mention the lock on the pump. I don't know if the Park pumps have one. If they do, it''s a small lever on the pump head that compresses the gasket. Put the pump on the valve with it off. Lock it pefore pumping and release before knocking the pump off.

Taking these precautions,you should be able to pump up tires for years with very few bent valve tips (or tube failures from flexing the valve when pumping).. I rode presta valves, expensive sew-up tires and did all of my inflating with a frame pump for 20 years. I killed 2 or three tires by the valve over those years. (We didn't have replaceable valves. Now you can buy tubes with replaceable valves so when you do bend a tip, it's no big deal. Look at the box next time you buy a tube. It will say replaceable velve if it has one. Pick up a couple of spare valves when you buy that tube.

Ben

Be glad you aren't in Japan where most bikes come with Woods valves.

Just make sure you are putting the pump head on straight, and hold it straight as you move the locking lever. If you bend the stem, you can bend it back easily enough with your finders. Or you can get a Schrader adapter for a few cents and use a normal pump.

ditch the ancient technology. drill them out & buy reliable & durable schrader valves. look for the ones with long stems

+1 to supporting the pump head as 79pmooney suggested. I learned that lesson the hard way, a long time ago and haven't bent or broken a presta valve since. I cradle the pump head in the palm of my left hand while pumping with my right hand. You don't have to use the most expensive pump either. The pump is a cheap $8 Giyo frame mounted pump and it will pump a 700CX23 tire rock hard.

Presta valves are not ancient technology. When we started to import quality bikes from Europe most came with presta valves. At the time hand pumps didn't work as well on schrader valves as for presta and that is why many of us used them.
Schrader valves have been around a very long time. from Wikipedia The Schrader company, for which it was named, was founded in 1844 by August Schrader. The original Schrader valve design was invented in 1891, and patented in the United States in 1893. You can't find much more ancient than that!

Assuming that you mean drill out the rims for schrader valves- that could work with ancient technology box section rims.


I can't recall actually messing up a presta valve over many decades, but it may have happened once or twice.